In my opinion, the fresh water tank installations in the Heartland trailers are problematic. I have a Cyclone 3210 that I purchased in March of this year. I more often than not dry camp for a week or more at a time. I was looking forward to being able to have 110 gallons of fresh water, per the weight calculation sticker placed in my trailer. Much to my dismay, while preparing for our first trip, I could get only 50 gallons of water in the tank (I meter the amount of water I was putting in the trailer). After our the trip, the trailer was returned to the dealer. I was told by Heartland that the 3210 carries only 75 gallons of water, and the weight calculation sticker was wrong. When the dealer pulled the undercovering, part of the problem was obvious. The tank was installed at an angle, the front of the tank, where the pump intake is located was about 2 to 2 1/2 inches higher than the back of the tank. In the tank there was about 20 gallons of water that could never be drained from tank. In addition, the tank vents are located on the sides of the tank, about 1 inch below the top of the tank, so unless the vent hoses go up rather than exiting down, you will never be able to fill the tank to its rated capacity. My calculations show that for the size of tank I had, I had lost about 10 gallons of storage capacity for each inch of tank height not available. In addition, the pump intake is also located on the side of the tank, about 1 inch above the bottom of the tank - another 10 gallons or so that you could not get out, assuming the tank was installed level with the trailer, which was not the case in my trailer. I haven't pulled the undercover since I got my trailer back from the dealer, but the service person said they moved the pump intake to the bottom of the tank so I can completely drain it in the winter. After I pumped the tank "empty", the next water fill took about 55 gallons before I closed the back tank vents because they were flowing water ( I installed valves on all four to the tank vent lines). After closing the back vents, I was able to get a total of 68 gallons in the tank. I am assuming that the dealer did level the tank, sort of. My next step is to follow Loco's directions and move the vent hoses up to the back of the fill neck, where they should have been in the first place. I believe Heartland needs to rethink how they engineer and install the fresh water tanks in their trailers, or be up front about how much water the trailer will carry and how much will be lost when the trailer is being towed.